If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

C Language Modules For LLVM Still Being Tackled

03-20-2013, 02:00 PM

Phoronix: C Language Modules For LLVM Still Being Tackled

Last year at the LLVM developers' meeting it was proposed by an Apple engineer the concept of "modules" for C code in LLVM/Clang to replace the common development approach for C/C++ languages of including header files and passing the library to the linker. LLVM modules seek to take a different approach...

Comment

C and C++ really need this. The whole .h files and cross-file-forward-referencing thing are probably the biggest thing which makes C/C++ feel "dated" compared to languages with proper "module" systems (Java, D, C#, etc). Hopefully it can be done as a standard, or at least added to GCC as well.

Comment

Awesome, about time. Now let us hope this gets worked into the standard.

No, let's hope this get implemented and then standardized later.

Back in the old days Turbo Pasal compiled with similar lines/min as Borland C. However as there is *much* less to compile when there are no include files building a project in Pascal was much faster then with C. The situation only worsened with C++ as there much more code in the header files. Borland in the time tried to speed C compiling up while maintaining compatibility by introducing compiled header, which was just a memory dump of the data structures after compiling the headers. This precompiled header file could only could only be reused between C modules if the included file where exactly identical. This of course didn't work well.

It really is time to introduce something similar like the old Trubo Pascal:
Unit xxx; #import the interface of another module
Interface; #define function prtotypes of functions that are exported
Implementation; # function bodies follow here

Comment

Stroustrup and friends have surely looked at modules, and possibly considered it for the next standard. Probably helps if Clang developers do this first though.
Also, for template heavy libraries, like boost can be, the gains aren't really that great.

Seems like Clang would make use it this in a very smart way, which is nice to hear.
The "futuristic" version doesn't really seem feasible though, especially for C++.

Comment

How dare they attempt to fork the tried and true standard and do their own thing!!!!!!!!!!

Oh, LLVM has nothing to do with Canonical?

I mean, what a great initiative, good for them!!!!

On a slightly more serious note, C is a low level language, and there's no reason to ever screw with it, C89 and C99 should continue being the standard dialects for all of eternity. C has a niche in low level, high performance STANDARDIZED UNIX-like code, this is another fine example of the stupidity of LLVM. Who would re-write their C code for LLVM so that they can lose 50% of their performance but gain some useless "compiler modularity"?

C++ has always sucked, confusing syntax, confusing memory management, and is pretty much a memory leak waiting to happen. I guess it's better than the proven failures that managed languages like C# and Java are, but falls short of the interpreted languages like Python and Perl for ease of use. It's funny to hear supposed Linux fanboys speak of C# as if it was some holy grail, what great ground breaking applications were written in C#? Answer: there are none. Even big name Java applications like Netbeans and Eclipse are so slow and buggy, they'd be better off written in PyQt than Java.